/*
 * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
 * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
 *
 * May be copied or modified under the terms of the GNU General Public
 * License.  See linux/COPYING for more information.
 *
 * Packet writing layer for ATAPI and SCSI CD-R, CD-RW, DVD-R, and
 * DVD-RW devices.
 *
 */
#ifndef __PKTCDVD_H
#define __PKTCDVD_H

#include <linux/types.h>

/*
 * 1 for normal debug messages, 2 is very verbose. 0 to turn it off.
 */
#define PACKET_DEBUG		1

#define	MAX_WRITERS		8

#define PKT_RB_POOL_SIZE	512

/*
 * How long we should hold a non-full packet before starting data gathering.
 */
#define PACKET_WAIT_TIME	(HZ * 5 / 1000)

/*
 * use drive write caching -- we need deferred error handling to be
 * able to sucessfully recover with this option (drive will return good
 * status as soon as the cdb is validated).
 */
#if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
#define USE_WCACHING		1
#else
#define USE_WCACHING		0
#endif

/*
 * No user-servicable parts beyond this point ->
 */

/*
 * device types
 */
#define PACKET_CDR		1
#define	PACKET_CDRW		2
#define PACKET_DVDR		3
#define PACKET_DVDRW		4

/*
 * flags
 */
#define PACKET_WRITABLE		1	/* pd is writable */
#define PACKET_NWA_VALID	2	/* next writable address valid */
#define PACKET_LRA_VALID	3	/* last recorded address valid */
#define PACKET_MERGE_SEGS	4	/* perform segment merging to keep */
					/* underlying cdrom device happy */

/*
 * Disc status -- from READ_DISC_INFO
 */
#define PACKET_DISC_EMPTY	0
#define PACKET_DISC_INCOMPLETE	1
#define PACKET_DISC_COMPLETE	2
#define PACKET_DISC_OTHER	3

/*
 * write type, and corresponding data block type
 */
#define PACKET_MODE1		1
#define PACKET_MODE2		2
#define PACKET_BLOCK_MODE1	8
#define PACKET_BLOCK_MODE2	10

/*
 * Last session/border status
 */
#define PACKET_SESSION_EMPTY		0
#define PACKET_SESSION_INCOMPLETE	1
#define PACKET_SESSION_RESERVED		2
#define PACKET_SESSION_COMPLETE		3

#define PACKET_MCN			"4a656e734178626f65323030300000"

#undef PACKET_USE_LS

#define PKT_CTRL_CMD_SETUP	0
#define PKT_CTRL_CMD_TEARDOWN	1
#define PKT_CTRL_CMD_STATUS	2

struct pkt_ctrl_command {
	__u32 command;		/* in: Setup, teardown, status */
	__u32 dev_index;	/* in/out: Device index */
	__u32 dev;		/* in/out: Device nr for cdrw device */
	__u32 pkt_dev;		/* in/out: Device nr for packet device */
	__u32 num_devices;	/* out: Largest device index + 1 */
	__u32 padding;		/* Not used */
};

/*
 * packet ioctls
 */
#define PACKET_IOCTL_MAGIC	('X')
#define PACKET_CTRL_CMD		_IOWR(PACKET_IOCTL_MAGIC, 1, struct pkt_ctrl_command)

#ifdef __KERNEL__
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/cdrom.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>

/* default bio write queue congestion marks */
#define PKT_WRITE_CONGESTION_ON    10000
#define PKT_WRITE_CONGESTION_OFF   9000

struct packet_settings {
	__u32 size;		/* packet size in (512 byte) sectors */
	__u8 fp;		/* fixed packets */
	__u8 link_loss;		/* the rest is specified
				 * as per Mt Fuji */
	__u8 write_type;
	__u8 track_mode;
	__u8 block_mode;
};

/*
 * Very crude stats for now
 */
struct packet_stats {
	unsigned long pkt_started;
	unsigned long pkt_ended;
	unsigned long secs_w;
	unsigned long secs_rg;
	unsigned long secs_r;
};

struct packet_cdrw {
	struct list_head pkt_free_list;
	struct list_head pkt_active_list;
	spinlock_t active_list_lock;	/* Serialize access to pkt_active_list */
	struct task_struct *thread;
	atomic_t pending_bios;
};

/*
 * Switch to high speed reading after reading this many kilobytes
 * with no interspersed writes.
 */
#define HI_SPEED_SWITCH 512

struct packet_iosched {
	atomic_t attention;	/* Set to non-zero when queue processing is needed */
	int writing;		/* Non-zero when writing, zero when reading */
	spinlock_t lock;	/* Protecting read/write queue manipulations */
	struct bio *read_queue;
	struct bio *read_queue_tail;
	struct bio *write_queue;
	struct bio *write_queue_tail;
	sector_t last_write;	/* The sector where the last write ended */
	int successive_reads;
};

/*
 * 32 buffers of 2048 bytes
 */
#if (PAGE_SIZE % CD_FRAMESIZE) != 0
#error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
#endif
#define PACKET_MAX_SIZE		128
#define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)
#define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)

enum packet_data_state {
	PACKET_IDLE_STATE,	/* Not used at the moment */
	PACKET_WAITING_STATE,	/* Waiting for more bios to arrive, so */
	/* we don't have to do as much */
	/* data gathering */
	PACKET_READ_WAIT_STATE,	/* Waiting for reads to fill in holes */
	PACKET_WRITE_WAIT_STATE,	/* Waiting for the write to complete */
	PACKET_RECOVERY_STATE,	/* Recover after read/write errors */
	PACKET_FINISHED_STATE,	/* After write has finished */

	PACKET_NUM_STATES	/* Number of possible states */
};

/*
 * Information needed for writing a single packet
 */
struct pktcdvd_device;

struct packet_data {
	struct list_head list;

	spinlock_t lock;	/* Lock protecting state transitions and */
	/* orig_bios list */

	struct bio *orig_bios;	/* Original bios passed to pkt_make_request */
	struct bio *orig_bios_tail;	/* that will be handled by this packet */
	int write_size;		/* Total size of all bios in the orig_bios */
	/* list, measured in number of frames */

	struct bio *w_bio;	/* The bio we will send to the real CD */
	/* device once we have all data for the */
	/* packet we are going to write */
	sector_t sector;	/* First sector in this packet */
	int frames;		/* Number of frames in this packet */

	enum packet_data_state state;	/* Current state */
	atomic_t run_sm;	/* Incremented whenever the state */
	/* machine needs to be run */
	long sleep_time;	/* Set this to non-zero to make the state */
	/* machine run after this many jiffies. */

	atomic_t io_wait;	/* Number of pending IO operations */
	atomic_t io_errors;	/* Number of read/write errors during IO */

	struct bio *r_bios[PACKET_MAX_SIZE];	/* bios to use during data gathering */
	struct page *pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];

	int cache_valid;	/* If non-zero, the data for the zone defined */
	/* by the sector variable is completely cached */
	/* in the pages[] vector. */

	int id;			/* ID number for debugging */
	struct pktcdvd_device *pd;
};

struct pkt_rb_node {
	struct rb_node rb_node;
	struct bio *bio;
};

struct packet_stacked_data {
	struct bio *bio;	/* Original read request bio */
	struct pktcdvd_device *pd;
};
#define PSD_POOL_SIZE		64

struct pktcdvd_kobj {
	struct kobject kobj;
	struct pktcdvd_device *pd;
};
#define to_pktcdvdkobj(_k) \
  ((struct pktcdvd_kobj*)container_of(_k,struct pktcdvd_kobj,kobj))

struct pktcdvd_device {
	struct block_device *bdev;	/* dev attached */
	dev_t pkt_dev;		/* our dev */
	char name[20];
	struct packet_settings settings;
	struct packet_stats stats;
	int refcnt;		/* Open count */
	int write_speed;	/* current write speed, kB/s */
	int read_speed;		/* current read speed, kB/s */
	unsigned long offset;	/* start offset */
	__u8 mode_offset;	/* 0 / 8 */
	__u8 type;
	unsigned long flags;
	__u16 mmc3_profile;
	__u32 nwa;		/* next writable address */
	__u32 lra;		/* last recorded address */
	struct packet_cdrw cdrw;
	wait_queue_head_t wqueue;

	spinlock_t lock;	/* Serialize access to bio_queue */
	struct rb_root bio_queue;	/* Work queue of bios we need to handle */
	int bio_queue_size;	/* Number of nodes in bio_queue */
	sector_t current_sector;	/* Keep track of where the elevator is */
	atomic_t scan_queue;	/* Set to non-zero when pkt_handle_queue */
	/* needs to be run. */
	mempool_t *rb_pool;	/* mempool for pkt_rb_node allocations */

	struct packet_iosched iosched;
	struct gendisk *disk;

	int write_congestion_off;
	int write_congestion_on;

	struct device *dev;	/* sysfs pktcdvd[0-7] dev */
	struct pktcdvd_kobj *kobj_stat;	/* sysfs pktcdvd[0-7]/stat/     */
	struct pktcdvd_kobj *kobj_wqueue;	/* sysfs pktcdvd[0-7]/write_queue/ */

	struct dentry *dfs_d_root;	/* debugfs: devname directory */
	struct dentry *dfs_f_info;	/* debugfs: info file */
};

#endif /* __KERNEL__ */

#endif /* __PKTCDVD_H */
